System and Method for Detecting Use of a Wireless Device While Driving

ABSTRACT

A system for detecting the use of wireless devices such as a mobile phone, personal digital assistant (PDA), or pagers in a moving vehicle receives wireless signals inside a vehicle using a radio frequency (RF) sensor(s) and converts the RF signals into voltage signals. The voltage signals are then compared with known waveforms to determine if the wireless signals indicate a received call, if the received call is answered, a transmitted call, an SMS text message, data associated with internet browsing on a wireless device, or Bluetooth activity.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/222,260, entitled “System and Method for Detecting Use of a WirelessDevice While Driving,” which was filed on Aug. 6, 2008, which is herebyincorporated by reference.

TECHNICAL FIELD OF THE INVENTION

This disclosure relates to a system and method for detecting the use ofwireless devices, such as mobile phones, in vehicles.

BACKGROUND OF THE INVENTION

The use of wireless devices, such as cellular telephones or personaldigital assistants (PDA), by drivers who talk on the phone or send orread text messages while driving is thought to be a cause of distracted,erratic, and/or aggressive driving, especially among teenage drivers,and is believed to increase the likelihood of accidents. Some citiesrestrict cellular phone use while driving or require that drivers usehands-free mode on their wireless phone to talk while driving. Othercities are considering restricting the use of text messagingapplications while driving.

Additionally, parents desire to monitor their children's driving andcellular phone use, and fleet owners or insurance companies desire tomonitor drivers' cellular phone use for liability purposes.

As shown in FIG. 1, using a driving simulator, Ford compared theresponse of teenage and adult drivers to traffic events happening infront of them. As shown on the left portion of the chart, both groups ofdrivers missed about 3% of potentially dangerous events under normalsimulated driving conditions. When placing a phone call using ahands-free device, as shown on the right portion of the chart, the rateof missed events rose to 13.6% for adult drivers and to 53.80/0 forteenage drivers.

Therefore, there is a need to improve driver behavior and safety withrespect to the use of wireless devices in moving vehicles.

SUMMARY OF THE INVENTION

The present invention is directed to a system and method of detectingthe use of wireless devices such as a mobile phone, personal digitalassistant (PDA), or pager in a moving vehicle. The invention receiveswireless signals inside a vehicle using a radio frequency (RF) sensorand converts the RF signals into voltage signals. The voltage signalsare then compared with known waveforms to determine if the wirelesssignals indicate a received call, if the received call is answered, atransmitted call, an SMS text message, data associated with internetbrowsing on a wireless device, or Bluetooth activity.

In an embodiment of the present invention, the number of passengers in avehicle is monitored. The number of passengers may be determined bydiscriminating among multiple wireless signals, or may be determined byusing various vehicle sensors, including seat belt sensors, seat weightsensors, airbag sensors, tire pressure sensors, and others.

Further features of the present invention, as well as the structure andoperation of various embodiments of the present invention are describedin detail below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference numbers indicate identical orfunctionally similar elements. Additionally, the left-most digit(s) of areference number identifies the drawing in which the reference numberfirst appears.

FIG. 1 is a chart comparing the percentage of events not detected amongadult and teenage drivers while placing a phone call and under regulardriving conditions;

FIG. 2 is a block diagram of an RF sensing device for detecting wirelesssignals in a moving vehicle;

FIG. 3 is a block diagram of a directional RF sensing device fordetecting wireless signals in a moving vehicle;

FIG. 4 is a block diagram of multiple RF sensing devices for detectingwireless signals in a moving vehicle;

FIG. 5 is a block diagram of a processor configured to detect wirelesssignals in a moving vehicle;

FIG. 6 is a state diagram for the detection of wireless signals in amoving vehicle;

FIG. 7 is a flowchart of a method for detecting wireless signals in amoving vehicle;

FIG. 8 is a waveform of a TDMA received voice call;

FIG. 9 is a waveform of a TDMA transmit voice call;

FIG. 10 is a waveform of a TDMA received unanswered voice call;

FIG. 11 is a waveform of a TDMA received and answered voice call;

FIG. 12 is a waveform of a TDMA transmit voice call;

FIG. 13 is a waveform of a TDMA transmit voice call;

FIG. 14 is a waveform of a TDMA SMS text message;

FIG. 15 is a waveform of a TDMA SMS sending text message;

FIG. 16 is a waveform of a TDMA SMS receiving text message;

FIG. 17 is a waveform of a TDMA SMS sending text message;

FIG. 18 is a waveform of a TDMA SMS sending text message;

FIG. 19 is a waveform of a CDMA sending data;

FIG. 20 is a waveform of a CDMA sending data;

FIG. 21 is a waveform of a CDMA sending data;

FIG. 22 is a waveform of a TDMA surfing the web;

FIG. 23 is a waveform of a TDMA surfing the web;

FIG. 24 is a waveform of a TDMA surfing the web;

FIG. 25 is a waveform of a TDMA surfing the web;

FIG. 26 is a waveform of a TDMA surfing the web;

FIG. 27 is a waveform of a TDMA mobile phone at 900 and 0° to sensingantenna;

FIG. 28 is a waveform of Bluetooth discovery mode; and

FIG. 29 is a waveform of Bluetooth discovery mode.

DETAILED DESCRIPTION OF THE INVENTION

A system for detecting the use of wireless devices in a moving vehicleincludes an input for receiving signals indicative of wirelesstransmissions, a processor for characterizing the received signals, andan output for mobile device use notification. Wireless devices include,for example, mobile phones, wireless messaging devices, personal digitalassistants (“PDA”), data communication devices, and the like.

Many different strategies may be employed for the detection of wirelesstransmissions. For example, in some implementations, an antenna is usedto receive wireless signals. When wireless signals are received, theyare characterized to determine their nature. For example, a mobile phoneperiodically broadcasts information even when it is not in use.Accordingly, the system is capable of differentiating varioustransmissions using signal processing techniques, such as the following:(1) filtering the received signals; (2) detecting identifyingcharacteristics of the received signals; (3) performing a statisticalanalysis to determine the most likely signal characterization; (4)neural networks; (5) and the like. In this manner, actual use can bedifferentiated from receipt of text messages, receipt of emails,voicemail notification, cell handoffs and control signaling, etc.

When a single antenna is used, it can be difficult to differentiatetransmissions from inside the vehicle and transmissions from mobiledevices outside the vehicle. Further, a single antenna may make itdifficult to determine whether a mobile device is being used by thedriver or a passenger. Accordingly, in some embodiments, multiplesensors are used together with signal processing to determine thelocation of the transmission source. For example, two or more antennas,microphones, or other sensors can be used to each receive the sametransmission. Using known signal processing techniques, the differencesbetween the amplitude and phase of the received signals can be used tocalculate the location of the transmission source. In this manner, it ispossible to differentiate mobile device use by the driver from mobiledevice use by a passenger or by someone external to the vehicle.

Once cell phone use is detected, appropriate notifications can be made.The notifications sent by the system can be varied depending on theintended implementation. For example, in a teenage driver safetymentoring system, notifications can be sent to parents whenever cellphone is used in a moving car. Implementations may include one or moreof the following: (1) notifying the driver of unsafe mobile deviceutilization in a moving vehicle; and (2) notifying someone other thanthe driver (e.g., a parent, insurance company, parole officer, police,and the like) of unsafe mobile device utilization in a moving vehicle.

Various implementations of systems and methods for detecting the use ofmobile devices are described herein below. In one implementation, adevice receives wireless signals inside a vehicle using a radiofrequency (RF) sensor and converts the RF signals into voltage signals.The voltage signals are then compared with known waveforms to determineif the wireless signals indicate a received call, if the received callis answered, a transmitted call, an SMS text message, data associatedwith internet browsing on a wireless device, or Bluetooth activity.

Determining Mobile Device Usage

Referring now to FIG. 2, a device is provided to detect the use ofmobile devices in a moving vehicle. A driver's cell phone 201 broadcastsand receives wireless signals. Similarly, another cell phone 203 islocated nearby, either with a passenger in the same vehicle or in anearby vehicle. While driver's cell phone 201 and nearby cell phone 203are both cell phones, one or both could be another wirelesscommunications device, such as a personal digital assistant (PDA).Alternatively, one or both of cell phones 201 and 203 could be aBluetooth hands-free device that communicates wirelessly with a mastercell phone located near the Bluetooth device. Bluetooth, as is known inthe art, is a wireless communications standard used in short-rangecommunications.

Referring again to FIG. 2, a power detector 205 receives wirelesssignals through its antenna, powered by a power supply 207. The antennais preferably tuned to the quad-band frequencies used by wirelessdevices, which are 850, 900, 1800, and 1900 MHz, which includes TDMA,GSM, and CDMA standards, as are known in the art. The power detector 205outputs a voltage waveform 209. The voltage waveforms are used todetermine the use of the mobile phone 201 or 203. Received amplitudelevels of the wireless signals are used to determine if the mobile phoneis that of the driver or that of another nearby user, such as apassenger or a nearby driver or passenger in a different vehicle.

As shown in FIG. 2, the driver cell phone 201 is located withinapproximately 2 feet of the power detector 205, while the nearby cellphone 203 is located approximately 4-8 feet from the power detector 205.

Using a simplified version of the free space loss equation, the receivedpower for the two different cell phones, 201 and 203, can be calculated.With isotropic (omni-directional) transmit and receive antennas having 0dBi gain, distance d=2 feet, transmit frequency f=900 MHz, transmitpower=4 watts, transmit distance greater than a wavelength thusprompting far-field equations, the free space loss is given as:

$\begin{matrix}{{{Free}\mspace{14mu} {space}\mspace{14mu} {loss}\mspace{14mu} ({dB})} = {36.56 + {20\mspace{14mu} \log \mspace{14mu} \left( {{d/5}\; 280} \right)} + {20\mspace{14mu} \log \mspace{14mu} (1)}}} \\{= {36.56 + {20\mspace{14mu} \log \mspace{14mu} \left( {{2/5}\; 280} \right)} + {20\mspace{14mu} \log \mspace{14mu} (900)}}} \\{= {27.2\mspace{14mu} {dB}}}\end{matrix}$

Thus, the received power is calculated as:

$\begin{matrix}{{{Received}\mspace{14mu} {antenna}\mspace{14mu} {power}\mspace{14mu} ({dB})} = {{20\mspace{14mu} \log \mspace{14mu} \left( {{transmit}\mspace{14mu} {power}} \right)} - {{free}\mspace{14mu} {space}\mspace{14mu} {loss}}}} \\{= {{20\mspace{14mu} \log \mspace{14mu} (4)} - 27.2}} \\{= {{- 15}\mspace{14mu} {dB}}}\end{matrix}$

This decibel level converts to approximately 2V in the log-voltageconverter. Doubling the distance to 4 feet results in 6 dB less, or −21dB, which converts to 1.3V. That is approximately 200 mV per foot ofdistance from the receiver.

Using an isotropic receive antenna, various other factors affectreceived power level. Examples of these factors include multi-patheffects, the type of radio, the distance from a tower, and phoneorientation. More specifically, multi-path effects include reflectionsoff of objects causing standing waves. TDMA (time division multipleaccess) and CDMA (code division multiple access) cell phones havedifferent transmission power levels. As a cell phone moves away from acell tower, the cell phone increases transmission power, and vice versa.Also, when a cell phone is held vertically or at an angle, the powertransmission level changes, as power radiates mainly away from the head,usually in a cardioid shape. All of these factors combine to makereceived power levels of a driver's cell phone or of a nearby cell phonedifficult to distinguish with an isotropic antenna. With a directionalantenna, such as an antenna that attenuates driver side-to-side RF powerby at least 10 dBi, many of these conflicting power levels are able tobe more easily differentiated. Various power conditions are shown in thetable below:

Effect Description Typical Variability Phone orientation +/−6 dB or+/−0.25 volts Multi-path effects +/−6 dB or +/−0.25 volts Distance froma tower +/−10 dB or +/−0.4 volts TDMA/CDMA radio +/−6 dB or +/−0.25volts Driver distance from power detector +/−5 dB or +/−0.2 volts

A minimum power threshold prevents the power detector from measuring allreceived signals. Instead, the power detector only converts wirelesssignals of nearby cell phones into voltage waveforms. The minimum powerthreshold can be a moving or learning threshold. Additionally, two ormore thresholds can be used to discriminate between outside cell phones,passenger cell phones, and driver cell phones.

Referring now to FIG. 3, there is shown a directional antennaillustrating in more detail the concepts described above. In FIG. 3,driver cell phone antenna 301 and passenger cell phone antenna 303 arelocated a distance d1 and d2 from receive antenna 305, respectively. Thereceive antenna 305 is directional and favors the driver cell phonesignal by at least 10 dBi over the passenger cell phone signal. Theoutput voltage Vd is used to differentiate between the driver signal andthe passenger signal. Two thresholds, Vdt and Vpt, are calibrated todetect the driver cell phone voltage and passenger cell phone voltage,respectively. For the driver signal, Vd<Vdt, and for the passengersignal, Vd>Vpt. Thus, the directional antenna 305 can be used todetermine whether a received signal is from the driver cell phone 301 orthe passenger cell phone 303 by comparing Vd to Vdt and Vpt.

Referring now to FIG. 4, there is shown an alternate antenna design. Thedriver antenna 401 and the passenger antenna 403 broadcast and arereceived by a first antenna 405 and a second antenna 407, which areidentical antennas located some distance apart. The spacing betweenfirst antenna 405 and second antenna 407 allows the two antennas, incombination, to determine the location of various received signals. Thedriver antenna 401 is located a distance d1 from the two antennas 405and 407, while the passenger antenna 403 is located a distance d2 fromthe two antennas 405 and 407. The distance d1 is approximately the samebetween the driver antenna 401 and the first antenna 405 and the driverantenna 401 and the second antenna 407, because two antennas 405 and 407are located near enough to each other that the difference between thedriver antenna 401 and the first antenna 405 and the driver antenna 401and the second antenna 407 is negligible.

The output waveform 409 is the difference between the voltage from thefirst antenna V1 and the voltage from the second antenna V2. Asdescribed above with respect to FIG. 3, the output voltage Vd is used todifferentiate between the driver signal and the passenger signal. Twothresholds, Vdt and Vpt, are calibrated to detect the driver cell phonevoltage and passenger cell phone voltage, respectively. For the driversignal, Vd<Vdt, and for the passenger signal, Vd>Vpt.

Referring now to FIG. 5, there is illustrated therein a processor thatuses the voltage waveform 209 as shown in FIG. 2 to determine the exactcell phone usage. In FIG. 5, the input voltage Vd is passed through alow pass filter 501 to a 10-12 bit ADC 503 and a comparator 505. Bywaveform analysis, a voltage trigger level is created by a 10-12 bit DAC507 and is passed to a comparator trigger level input 509. The processormay be an FPGA, ASIC, or other logic device, as is known in the art.

In more detail, an input voltage Vd, in the form of pulses, is passedthrough a low pass filter 501, e.g., a 2nd order Sallen-Key with fc=5KHz. The voltage waveform Vd as described above of approximately 4 mVper 0.1 dB, ranges from 0.2V or −60 dB to 2.4V or −5 dB. The waveform Vdis passed into comparator 505, and the transitions crossing thecomparator trigger level create interrupts on both positive and negativeedge crossings. The time between the positive and negative crossinginterrupts is the pulse duration. During each active pulse duration, theADC 503 measures the average pulse amplitude. The average amplitude isused for differentiation between the driver, passenger, and other nearbycell phone signals. The average amplitude is also used foridentification of amplitude variations from phone proximity,orientation, and multi-path.

Using a comparator and state machines with stored memory, a tablelookup, digital signal processing, neural network processing, or othermethod, the processor determines whether the voltage waveform indicatesa voice call, a text message, internet browsing, Bluetooth activity, orother wireless activity. The processor also uses state-machineconfidence counters to determine confidences about waveformdeterminations. Confidence counter thresholds, which may be set at anylevel and may be adaptive, represent a “high likeness” level ofdetection of a certain type or types of waveform. Confidence countersare weighted toward the “no confidence” or “zero confidence” state.Confidence counter outcomes map, in combination with each other, towaveform identification tables. Additionally, over time, the processorlearns the particular cell phone voltage pattern and movement.

Referring now to FIG. 6, there is illustrated a state flow diagram of apreferred embodiment of the state machine concept described above. Theprocessor of FIG. 5 measures pulse duration and pulse amplitude. Thesampled waveform 601 is then compared to look-up tables 603. Thelikeliest pulse type 605 is determined by the measured pulse width time,inter-pulse times, and by feedback from other processes. The likeliestpulse group type 607 is determined by timing behind groups of likeliestpulse types 605 and by feedback from other processes. The likeliestpulse group collection type 609 is determined by timing behind acollection of pulse group types 607 and by feedback from otherprocesses. The likeliest waveform decision 611 is determined by thelikeliest types that were determined by the other processes. All ofthese processors include comparator trigger level calculations.

The processor can store local data relating to cell phone usage, as wellas store a library of known cell phone wireless signals converted tovoltage waveforms. Additionally, the processor may communicate with aremote server in order to update a library of known cell phone wirelesssignals converted to voltage waveforms. The server may also storeinformation relating to measured cell phone usage, backing up the memoryof the processor or replacing the memory. In this way, over time, thelibrary of stored voltage waveforms can be adapted or updated.

Power detector 205 of FIG. 2 can include additional sensors orcommunication interfaces to receive additional data. For example, powerdetector 205 may include a directional microphone to monitor voicesounds and other sounds, in order to more precisely determine locationand user of a mobile phone. Power detector 205 may additionally includea motion sensor, such as a global positioning (GPS) device,accelerometer, or other motion sensing device, that monitors speedand/or location of the power detector. The speed and/or location may bestored and correlated with the voltage waveforms indicative of mobilephone usage.

Power detector 205 of FIG. 2 can also be used to detect wireless signalsemitted from a transmitter attached to the vehicle rather than held by adriver or passenger. Some vehicles include docking or mounting stationsfor mobile devices and control the operation of the mobile device uponreceiving directions from the driver or passenger.

The power detector 205, as well as additional sensors, and power supply207, voltage output 209, and other components are preferably located ina single housing, or may be located in multiple housings. The singlehousing may be preferably affixed to the windshield of a vehicle, or maybe located above or below the driver.

Indirect Mobile Device Usage Detection

In some implementations, mobile phone usage may be determinedindirectly. A camera sensor similar to a blink rate sensor may be usedto look for a driver's hand to either ear. Another embodiment fordetecting cell phone use would be to monitor the vehicle's average pathdeviation per a given time and/or distance interval using a highprecision positioning system, i.e., DGPS, WAAS, RTK or other equivalent.The positioning system would be used to compare normal driving withoutcommunication use to the driving performance while using a communicationdevice, e.g. monitor weaving and lane departure.

Determining Passenger Numbers

Referring again to FIG. 2, the power detector 205 can be used to measuretwo or more wireless signals and convert the signals to voltagewaveforms. Using the voltage waveforms, the number of nearby cell phonescan be determined.

Referring now to FIG. 7, there is shown a flowchart describing anoverall method of using the system described above with reference toFIGS. 2-6.

Initially, an antenna receives wireless signals 701. Then the wirelesssignals are converted to a voltage waveform 703. Next, the voltagewaveform is analyzed to determine the location and number of discretewireless signals 705. Finally, a number of mobile phone users in avehicle is determined using the analyzed voltage waveform 707.

Additionally, other sensors can be used to determine number ofpassengers in a vehicle. Each vehicle includes a sensing bus thatcommunicates with various vehicle sensors, including a seat belt sensor,a weight sensor in a passenger seat used for air bag deployment, andother sensors.

The power detector 205 can also store passenger number data andcorrelate this information with speed and/or location data received fromthe motion sensor. In this way, a vehicle with a restricted number ofpassengers, such as a vehicle driven by a teenage or a vehicle driven bya driver in fleet with passenger restrictions, can be monitored.

Determining Waveforms

Received wireless signals converted into waveforms distinctly show thetype of cell phone usage. Measured voltage waveforms are shown below inFIGS. 8-29, illustrating various voltage waveforms in TDMA, GSM, andCDMA wireless systems under various circumstances, including receivedand transmitted calls, answered and unanswered calls, text messaging,internet browsing, and Bluetooth activity. Voltage waveforms for otherfrequency wireless signals including satellite band, handheld radios,etc., may also be measured.

In FIGS. 8-29, a Q-wave antenna tuned to 1370 MHz, midway between 800and 1900 MHz, is connected with an SMA connector to a Linear Tech 748ARF power log-voltage detector powered by a 5V power supply. The powerdetector has a 0 to 60 dB dynamic range, which corresponds to a minimummeasurable signal level of −60 dB converted to 0.2 volts and a maximummeasurable level of 0 dB converted to 3 volts.

As shown in FIGS. 8-29, answered and unanswered received calls havedifferent waveforms, while data waveforms for text messages and internetbrowsing are distinguishable from voice calls. Thus, by comparingreceived voltage waveforms to known voltage waveforms, exact mobilephone usage can be determined.

Referring now to FIGS. 8 and 9, the waveform for a TDMA voice call isshown. In FIG. 8, a received voice call has a voltage above thethreshold, with short voltage peaks and tall voltage peaks. There isapproximately 4.5 ms between short peaks and approximately 9 ms betweentall peaks. In FIG. 9, a transmitted voice call has a voltage above thethreshold, with short voltage peaks and tall voltage peaks. There isapproximately 4.5 ms between short peaks and approximately 9 ms betweentall peaks.

Referring now to FIGS. 10 and 11, the waveform for a TDMA received voicecall is shown. In FIG. 10, a received but not answered voice call has avoltage above the threshold, with short voltage peaks and tall voltagepeaks. There is a regular non-bursting pattern with approximately 4.5 msbetween short peaks and approximately 9 ms between tall peaks. In FIG.11, a received and answered voice call has a voltage above thethreshold, with short voltage peaks and tall voltage peaks. There is acoarse bursting pattern with approximately 4.5 ms between short peaksand approximately 9 ms between tall peaks.

Referring now to FIGS. 12 and 13, the waveform for a TDMA transmittedvoice call is shown. In FIG. 12, a transmitted voice call has a voltageabove the threshold, with short voltage peaks and tall voltage peaks.There is a fine bursting pattern with approximately 4.5 ms between shortpeaks and approximately 9 ms between tall peaks. In FIG. 13, atransmitted voice call has a voltage above the threshold, with shortvoltage peaks and tall voltage peaks. There is a fine bursting patternwith approximately 4.5 ms between short peaks and approximately 9 Insbetween tall peaks.

Referring now to FIGS. 14-18, the waveform for a TDMA SMS text messageis shown. In FIG. 14, a sent text message has a voltage above thethreshold, with short voltage peaks and tall voltage peaks. There is acoarse bursting pattern with approximately 4.5 ms between short peaksand approximately 9 ms between tall peaks. In FIG. 15, a sent textmessage has a voltage above the threshold, with short voltage peaks andtall voltage peaks. There is a coarse bursting pattern withapproximately 4.5 ms between short peaks and approximately 9 ms betweentall peaks. In FIG. 16, a received text message has a voltage above thethreshold, with short voltage peaks and tall voltage peaks. There is acoarse bursting pattern with approximately 4.5 ms between short peaksand approximately 9 ms between tall peaks. In FIG. 17, a sent textmessage has a voltage above the threshold, with short voltage peaks andtall voltage peaks. There is a coarse bursting pattern withapproximately 4.5 ms between short peaks and approximately 9 ms betweentall peaks. In FIG. 18, a sent text message has a voltage above thethreshold, with short voltage peaks and tall voltage peaks. There is acoarse bursting pattern with approximately 4.5 ms between short peaksand approximately 9 ms between tall peaks.

Referring now to FIGS. 19-21, the waveform for a CDMA text message isshown. In FIG. 19, a sent text message has a voltage above thethreshold, with voltage peaks. There is a coarse bursting pattern withapproximately 3 ms between peaks. In FIG. 20, a sent text message has avoltage above the threshold, with voltage peaks. There is a coarsebursting pattern with approximately 3 ms between peaks. In FIG. 21, asent text message has a voltage above the threshold, with voltage peaks.There is a coarse bursting pattern with approximately 3 ms betweenpeaks.

Referring now to FIGS. 22-26, the waveform for a TDMA data transmissionduring internet browsing is shown. In FIG. 22, a sent text message has avoltage above the threshold, with short voltage peaks and tall voltagepeaks. There is a coarse bursting pattern with approximately 4.5 msbetween large peaks. In FIG. 23, a sent text message has a voltage abovethe threshold, with short voltage peaks and tall voltage peaks. There isa coarse bursting pattern with approximately 4.5 ms between large peaks.In FIG. 24, a sent text message has a voltage above the threshold, withshort voltage peaks and tall voltage peaks. There is a coarse burstingpattern with approximately 4.5 ms between large peaks. In FIG. 25, asent text message has a voltage above the threshold, with short voltagepeaks and tall voltage peaks. There is a coarse bursting pattern withapproximately 4.5 ms between large peaks. In FIG. 26, a sent textmessage has a voltage above the threshold, with short voltage peaks andtall voltage peaks. There is a coarse bursting pattern withapproximately 4.5 ms between large peaks.

Referring now to FIG. 27, there is shown a TDMA waveform when a phone isused at 90° and at 0° to the sensing antenna. As shown, there is a 5-10dB amplitude variation in signal strength, translated to a voltagechange, depending upon the orientation of the mobile phone to thesensing antenna.

Referring now to FIGS. 28 and 29, the waveform for Bluetooth discoverymode is shown. In FIG. 28, the Bluetooth discovery mode has a voltageabove the threshold, with short voltage peaks and tall voltage peaks.There is a bursting pattern with 4-5 large peaks every 40 ms withapproximately 5 ms between peaks. In FIG. 29, the Bluetooth discoverymode has a voltage above the threshold, with short voltage peaks andtall voltage peaks. There is a bursting pattern with 4-5 large peaksevery 40 ms with approximately 5 ms between peaks.

While various embodiments of the present invention have been describedabove, it should be understood that they have been presented by way ofexample only and not limitation. It will be understood by those skilledin the art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the invention as definedin the appended claims. Thus, the breadth and scope of the presentinvention should not be limited by any of the above-described exemplaryembodiments, but should be defined only in accordance with the followingclaims and their equivalents.

What is claimed is:
 1. A device for detecting wireless signals in avehicle, comprising: a first antenna operable to receive a wirelesssignal; a second antenna operable to receive the wireless signal; apower detector, located in a vehicle, connected to the first antenna andthe second antenna, the power detector operable to convert the wirelesssignal into a voltage waveform; a motion sensor; and a processorcommunicatively coupled to the power detector and the motion sensor,wherein the processor is operable to: receive the voltage waveform;compare the voltage waveform to at least one pre-determined pattern;determine mobile device usage based at least in part on the comparisonof the voltage waveform to the at least one pre-determined pattern; andcorrelate the determined mobile device usage with motion data indicatingthat the vehicle is in motion received from the motion sensor.
 2. Thedevice of claim 1, wherein the power detector is further operable todetermine a magnitude of the wireless signal.
 3. The device of claim 2,wherein the power detector converts the wireless signal into the voltagewaveform in response to determining that the magnitude of the wirelesssignal exceeds a power threshold.
 4. The device of claim 1, wherein thefirst antenna is omnidirectional.
 5. The device of claim 1, wherein thepower detector is further operable to determine a first magnitude of thewireless signal received at the first antenna; and determine a secondmagnitude of the wireless signal received at the second antenna.
 6. Thedevice of claim 5, wherein the power detector is further operable todetermine the wireless signal is associated with a mobile device in useinside of the vehicle based at least in part upon the difference betweenthe first magnitude and the second magnitude.
 7. The device of claim 5,wherein the power detector is further operable to determine the wirelesssignal is associated with a mobile device in use by a driver of thevehicle based at least in part upon the difference between the firstmagnitude and the second magnitude.
 8. The device of claim 1, whereinthe processor is further operable to: determine a combination pulseamplitude associated with the voltage waveform; and determine thewireless signal is associated with a mobile device in use inside of thevehicle based at least in part upon the combination pulse amplitude. 9.The device of claim 1, further comprising a seat belt sensor and whereinthe processor is further operable to: correlate seat belt sensor datareceived from the seat belt sensor with the determined mobile phoneusage; and determine a location of a user based at least in part uponthe correlation of the seat belt sensor data with the determined mobilephone usage.
 10. A method for detecting wireless signals in a vehicle,comprising: receiving a wireless signal at a first antenna; receivingthe wireless signal at a second antenna; converting, using a powerdetector located in a vehicle, the wireless signal into a voltagewaveform, wherein the power detector is connected to the first antennaand the second antenna; receiving, at a processor, the voltage waveform;comparing the voltage waveform to at least one pre-determined pattern;determining mobile device usage based at least in part on the comparisonof the voltage waveform to the at least one pre-determined pattern; andcorrelating the determined mobile device usage with motion dataindicating that the vehicle is in motion received from a motion sensor.11. The method of claim 10, further comprising determining a magnitudeof the wireless signal.
 12. The method of claim 11, wherein convertingthe wireless signal into the voltage waveform is in response todetermining that the magnitude of the wireless signal exceeds a powerthreshold.
 13. The method of claim 10, wherein the first antenna isomnidirectional.
 14. The method of claim 10, further comprising:determining a first magnitude of the wireless signal received at thefirst antenna; and determining a second magnitude of the wireless signalreceived at the second antenna.
 15. The method of claim 14, furthercomprising determining the wireless signal is associated with a mobiledevice in use inside of the vehicle based at least in part upon thedifference between the first magnitude and the second magnitude.
 16. Themethod of claim 14, further comprising determining the wireless signalis associated with a mobile device in use by a driver of the vehiclebased at least in part upon the difference between the first magnitudeand the second magnitude.
 17. The method of claim 10, furthercomprising: determining a combination pulse amplitude associated withthe voltage waveform; and determining the wireless signal is associatedwith a mobile device in use inside of the vehicle based at least in partupon the combination pulse amplitude.
 18. The method of claim 10,further comprising: correlating seat belt sensor data received from aseat belt sensor with the determined mobile phone usage; and determininga location of a user based at least in part upon the correlation of theseat belt sensor data with the determined mobile phone usage.
 19. Awireless signal detection system, comprising: a first antenna operableto receive a wireless signal, wherein the first antenna isomnidirectional; a second antenna operable to receive the wirelesssignal; a power detector, located in a vehicle, connected to the firstantenna and the second antenna, the power detector operable to:determine a first magnitude of the wireless signal received at the firstantenna; convert the wireless signal into a voltage waveform in responseto determining the first magnitude of the wireless signal exceeds apower threshold; a motion sensor; and a processor communicativelycoupled to the power detector and the motion sensor, wherein theprocessor operable to: receive the voltage waveform; compare the voltagewaveform to at least one pre-determined pattern; determine mobile deviceusage based at least in part on the comparison of the voltage waveformto the at least one pre-determined pattern; and correlate the determinedmobile device usage with motion data indicating that the vehicle is inmotion received from the motion sensor.
 20. The system of claim 19,wherein the power detector is further operable to determine a secondmagnitude of the wireless signal received at the second antenna.
 21. Thesystem of claim 20, wherein the power detector is further operable todetermine that the wireless signal is associated with a mobile device inuse inside of the vehicle based at least in part upon the differencebetween the first magnitude and the second magnitude.
 22. The system ofclaim 19, wherein the processor is further operable to: determine acombination pulse amplitude associated with the voltage waveform; anddetermine the wireless signal is associated with a mobile device in useinside of the vehicle based at least in part upon the combination pulseamplitude.
 23. The system of claim 19, further comprising a seat beltsensor and wherein the processor is operable to: correlate seat beltsensor data received from the seat belt sensor with the determinedmobile phone usage; and determine a location of a user based at least inpart upon the correlation of the seat belt sensor data with thedetermined mobile phone usage.